Home appliance control element



United rates atent ()fifice iifiiidfiiifl Patented Dec. 4., 19%2 This inversion relates to control devices and in particular to control knobs for use in appliances such as countertop ranges.

in drop-in type countertop ranges, the knobs associated with the controls for regulating the heating elements are conventionally arranged to project upwardly from the horizontally extending top panel of the range. This arrangement of the control knobs has the disadvantage of susceptibility thereof to damage, as by being struck by pots or the like being handled by the user of the range. Further, the highly desirable flush mounting appearance of the range is effectively impaired by such projecting elements. One solution to this problem has been to reduce the height of the control knobs to minimize their extension above the range top. This solution has the disadvantage of reducing facility with which the control knobs are manipulated and does not truly solve the problem but merely compromises it.

The present invention is concerned with a new and improved control knob structure which avoids the above discussed disadvantages of the conventional control knobs. A prin ipal feature of the present invention, therefore, is the provision of a new and improved control knob structure.

Another feature of the invention is the provision of such a control knob structure, for use in apparatus such as counter-top ranges, comprising an effectively flush mounted device.

A further feature of the invention is the provision of such a flush mounted control knob structure arranged for improved facilitated manipulation.

Still another eature of the invention is the provision of such a control knob structure arranged for facilitated association with and disassociation from the devices controlling the operation of the heating elements.

Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawing wherein:

FlGURE l is a plan view of a countertop range provided with control knobs embodying the invention, the range being illustrated as mounted in a portion of the con ventional countertop.

FlGURE 2 is an enlarged plan view of one of the control knobs installed in a portion of the range top.

FEGURE 3 is an enlarged vertical section taken substantially along the line 3-3 of FIGURE 1, the position of the manipulating portion of the knob for turning the knob being shown in broken lines.

FIGURE 4 is a vertical section of the control knob taken substantially along the line 4-4 of FIGURE 2.

FIGURE 5 is a reduced elevation of the control knob.

in the exemplary embodiment of the invention as disclosed in the drawing, a plurality of control knobs are provided in a drop-in type countertop range generally designated 11. In illustrating the invention, range 11 is shown as being provided with a plurality of electrical heating elements 12 controlled by individual switches 13, it being understood that where the heating elements comprise gaseous fuel burners, the control device may comprise control valves in lieu of the illustrated switches. As shown, the control knobs it) are arranged to be mounted substantiallz flush with the top plate 14 of range 11. Each control knob, as best seen in FIGURE 3, extends downwardly through an opening 15 in top plate 14 into operative association with switch 13 which may be carried on'top plate 14 by suitable means such as brackets 16 to be disposed directly below opening 15 and in spaced relation with the bottom pan it? of the range which is arranged to extend downwardly through an opening 13 in the countertop 19 carrying the range.

More specifically, each control knob lll includes a relatively heavy body 2i} having a cylindrical portion 21 extending vertically through opening 15 herein illustrated as circular. The diameter of body cylindrical portion 21 is made to be only slightly less than the diameter of open ing 15? whereby the body is relatively accurately rotatably fitted in the opening for rotation about the vertical axis thereof. 'ihe upper end of the body defines a front surface 22 upwardly into which opens a semispherical, coaxial recess 23. The periphery of surface 22 is defined by a thin annular flange 2 1 overlying the annular edge 25 of top plate 14 defining the opening 15. Herein, flange 24 rests slidably on plate portion 25 with top surface 22 of the body spaced only slightly above the top of plate 14 so as to be effectively flush therewith.

Rotation of body 2i? about its vertical axis is effected by suitable manipulation of a disc element 25 having a diameter slightly smaller than the diameter of recess 23 and pivotally mounted in the upper end of the recess on a pair of diametrically opposed pins 27 secured to body portion 21. The pins 27 are positioned so that when the disc is arranged perpendicular to the vertical axis of the body Zil, the upper surface 2% of the disc is substantially coplanar with body top surface 2 2. As best seen in FIG- URES 3 and 4, the pivotal movement of the disc is limited in direction (in the counterclockwise direction as seen in FEGURE 3) by means of a first stop pin 2 extending from body portion 21' inwardly toward the axis of recess 23 and spaced below top surface 22 of the body a distance substantially equal to the thickness of the disc, whereby the disc is automatically positioned in the transversely extending flush position across the upper end of the recess. A second stop pin 3b is secured to body 2% to extend verticaliy upwardly into the lower end of recess 23 to limit the pivotal movement of the disc in the opposite direction (in the clockwise direction as seen in FIGURE 3). The axis of stop pin 30 lies in the common plane of the axis of recess 23 and the axis of stop pin 29 extending perpendicularly to the axis of pivot pins 27. As best seen in FIGURE 3, stop pin Ell is offset, from the vertical plane defined by the axis of pins 27 and the vertical axis of recess 23, toward pin 29 a distance substantially equal to one-half the thickness of disc 26 whereby when the disc is pivoted into engagement with stop pin 3d it is disposed in a substantial vertical arrangement, as shown in dotted lines in FIGURE 3. Thus, stop pin 29 comprises means for automatically positioning the disc to be flush with the top surface of the body and close the upper end of the recess 23, and stop pin 3% comprises means for automatically positioning the disc to extend parallel to the vertical axis of body 2 whereby the body may be rotated about that by suitable manipulation of the disc.

Operation of switch 13 is effected by rotation of body 24 through a coupling therebetween defined by a downwardly opening cylindrical recess 29 of non-circular cross section in the lower end 34 of the body, and a complementary control shaft 31 extending upwardly from switch 13 into recess 29 providing non-rotative, axially movable association of body 20 with the control shaft. As indicated, body 20 is preferably relatively heavy, illustratively being formed of metal, whereby the association of the body with shaft 31 is maintained by the weight of the control knob. However, for purposes such as cleaning the control knob or providing access to the control switch, the control knob is readily removable from association with the control switch by the simple expedient of raising the control knob vertically. The non-circular transverse section of shaft 31 and recess 29 preferably provides for an engagement of the body with the shaft in a single rotational position of the body relative-to the shaft; herein the shaft is cylindrical and provided with a chordal, flat recess 29 being complementary thereto. Thus, the control knob may be used to indicate the condition of the control switch, as by the correlation of suitable markings 32 on the upper surface of flange 24 with an indicator 33 on plate 14 adjacent the flange.

In use, the control knob is normally arranged with the disc 26 extending across the top of the recess 23 flush with the body top surface 22, thereby closing the recess against the entry of foreign materials. When it is desired to operate'a control switch 13, the corresponding control knob is manipulated by the user by first depressing the portion of the disc opposite stop pin 29, thereby pivoting the disc about pivot pins 27, until the disc is substantially perpendicular to the flush arrangement, which position is automatically provided by the abutment of the disc with the stop pin 30. The user may now rotate the control knob about its vertical axis to rotate shaft 31 and thereby operate switch 13, by simply placing his thumb on one side of the vertically extending disc and one or more of his fingers on the opposite side of the disc and turning the disc and the body 20, to which the disc is secured, as desired. While the range is being used, the disc may be maintained in the vertical position, or may be restored to the horizontal position flush with the surface 22, as desired. Similarly, to return the control switch 13 to the OE position, the operator merely grasps the control disc disposed in the vertical arrangement to turn the control knob suitably to the off position.

The normal closure of the recess 23 elfectively precludes deposition of foreign material therein. The smooth semispherical configuration of the recess permits ready cleaning thereof to remove any such foreign material which may nevertheless accumulate therein. Further, the readily removable association of the control knob with the switch shaft permits facilitated cleaning of the space below opening 15 when desired.

Having described my invention as related to the embodiment shown in the accompanying drawing, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

The embodiment of the invention in which an exclusive property or privilege is claimed is defined as follows:

1. Apparatus comprising: a horizontal wall provided with an opening having a vertical axis; a member to be rotated extending coaxially to said opening and below the wall; a body coaxially rotatable in the opening and having a top surface defining an axial, upwardly opening recess and a lower portion having connecting means axially movably, non-rotatively connected to said member; a support element on said body slidably retained on the wall surrounding said opening substantially only by the weight of the body, said element being arranged to dispose the body with said top surface substantially flush with the upper surface of the wall; and a manipulating element pivotally mounted on said body in said recess to pivot about an axis transversely across the upper end of said recess to be selectively arranged substantially horizontally across the recess and flush with said surface and substantially vertically upright to project from said means; and cooperating means on at least one of said body and said element positively limiting the pivotal movement of said element.

2. The apparatus of claim 1 wherein said support element comprises a thin flange extending transaxially outwardly from the upper end of the body.

3. The apparatus of claim 1 wherein said support element comprises a thin, annular, peripheral flange extending transaxially outwardly from the upper end of the body.

4. The apparatus of claim 1 wherein said recess is semispherical.

5. The apparatus of claim 1 wherein said lower portion of the body is massive and includes a downwardly opening recess removably receiving said member to be rotated.

References Cited in the file of this patent UNITED STATES PATENTS 400,536 Bailey Apr. 2, 1889 1,322,979 Waite Nov. 25, 1919 2,115,068 Haley Apr. 26, 1938 2,294,686 Newman Sept. 1, 1942 2,357,328 Harris Sept. 5, 1944 2,405,683 Briskin Aug. 13, 1946 2,890,595 Loefiier June 16, 1959 FOREIGN PATENTS 820,913 Germany Nov. 15, 1951 

